1. Field of the Invention
The present invention relates generally to footwear, and in particular an article of footwear intended for use with a left and right foot.
2. Description of Related Art
Typically, a child may use a pair of footwear without understanding the difference between left and right, resulting in the wrong shoe being placed on the left or right foot. Additionally, because a child's shoes may have less variability between the left and right shoe, a parent may also easily make the mistake of putting the shoes on the wrong feet. There is a need in the art for footwear without these problems.
Inserts that include materials capable of conforming to the contours of a foot after they have been initially manufactured have been proposed. Wolps (U.S. Pat. No. 4,167,824) discloses an insole insert that comprises an open cell foam base capable of conforming to and substantially retaining the shape of compressive forces applied to the insole, an elastic closed cell foam layer having a maximum compression set of less than 50% and a stretch fabric bonded to one face of the closed cell foam layer. The drawback of this design is that the open cell foam may only mold to the foot of the wearer after repeated use. There is a need for a substantial “break in” period for the Wolps design.
Johnson (US patent application publication 2005/0138844) discloses a multi-layered insole that supports the foot, provides impact resistance, and conforms to the shape of the foot. It comprises a pliable yet supporting heel-cup layer, a high impact foam later that sets very little, and an image foam later that sets to the wearer's foot shape thereby forming a cushion fit to the foot bed. A drawback of this invention is that a heel cup is necessary to provide structure to the insole and other layers so that the insole holds its shape. However the heel cup does not extend over the full length of the insert. There is a need in the art for a foam based insert that molds to the foot and does not require the use of an additional heel cup for structural support.
Generally, these types of insoles require the shape of the foot to be set after a substantial period of time. This is because adult feet generally require a certain amount of support that may be provided by a fixed mold of the foot shape within the insert. As a child's feet do not require this degree of support, an insert may be configured to mold to the foot during use, without any substantial set of the foam or material after the foot has been removed.
There is therefore a need in the art for inserts that may be used with an article of footwear that may be used with either the left foot or the right foot. These inserts will generally be large enough to accommodate the features of both a left foot and a right foot. Additionally, the inserts will substantially deform during use, but return to a non-deformed state following use.
There is also a need in the art for an article of footwear including an upper and an outsole that are configured to be used with both a left foot and a right foot.